Understanding and Resolving Boiler Noises: Expert Guide
The noises coming from the boiler can provide clues about its operating condition. Each assessment should be carried out with a qualified technician.
The boiler can produce various noises, such as knocking, whistling, and vibrations. It’s crucial to check the heating system’s pressure level. If it is low, open the filling valve and wait for the water in the system to reach 1.2 / 1.5 bar. This can eliminate noises similar to something frying, indicating that the water is close to a state change in the Primary Heat Exchanger. When the water is close to turning into steam, the boiler may start to make loud increasing noises.
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Noises Related to Gas Valves
Some gas valves may become noisy after years of operation, manifesting as a loud knock when the flame ignites. In case of boilers dirty with limescale, you’ll hear the boiler continuously turning on and off. This is due to the technical water increasing in temperature, forcing the boiler to shut down. Then, the boiler turns on for 10 seconds and shuts off again, a cycle that can repeat 20-30 times during a shower. The limescale in the boiler significantly reduces the lifespan of gas valves. The valve opens the gas through a piston and an electric coil, and the noise comes from the piston’s movement, which eventually can break the valve, preventing it from opening the gas.
Noises Related to Smoke Extractors
Smoke extractors in forced-draft boilers can generate vibrations. These can be caused by ball bearings, the shaft, or the auxiliary cooling fan. Continuous vibration can be a sign that the fan needs replacement. Lubricated ball bearings can be a temporary solution, but often fan replacement is required.
Knocks from the Expansion Vessel
An improperly fixed or empty expansion vessel can contribute to loud noises. During the heating operation, a loose expansion vessel can cause intense vibrations and strike the boiler’s casing.
Increasing Noises
Increasing noises are often due to the state change of the boiler’s technical water. Lack of pressure or a blocked circulator can be common causes, as well as a clogged primary heat exchanger.
Inadequate Circulation
The noises coming from the boiler can give us hints about its operating condition. Each assessment should be performed with a qualified technician. The boiler can produce various noises, such as knocking, whistling, and vibrations. It’s important to check the pressure level of the heating system. If it is low, open the filling tap and wait for the system water to reach 1.2 / 1.5 bar. This can eliminate noises similar to something frying, a sign that the water is close to changing state in the Primary Heat Exchanger. When the water is near to becoming steam, the boiler can produce loud increasing noises.
- All Thermostatic Valves Closed and Lack of Bypass or Bypass Radiator: This situation can prevent proper water circulation, causing abnormal noises.
- Obstructed Primary Heat Exchanger: The obstruction of the exchanger can reduce water flow, causing noises similar to rustling or hissing.
- Dirty Magnetic Sludge Filter: If present, a dirty filter can reduce circulation and contribute to the increasing noises.
